CASP8 and prostate neoplasm: In contrast, 2, 4, and 8 μM sulforaphane alone did not induce DNA damage in both prostate tumor cell lines, but increased DNA damage in DU145 cells when combined with vitamin D. The augmented DNA damage probably results from induction of cell death, due to the elevated expression of the BAX, CASP3, and CASP8 proteins related to apoptotic cell death in DU145 cells.